Spinal Cord and Spinal Nerves Flashcards
Define spinal nerve and cauda equina
- 31 pairs in and out, part of the PNS for taking messages to anf from spinal cord
- mixed, caring both sencory and motor infor
- Cauda Equina to go inferior to spinal nerve, resembles horse tail
Describe the overall functions of the spinal cord
carries messages to and from the brain
-spinal reflexes
Describe the location of the spinal cord
-in the vertebral foramen, formen magnum to about L2 (spinal cord finishes developing before bones of spine do)
Describe the significance of the two spinal cord enlargments
Arms & legs nerves entering & exiting spinal cord
Name the protective covering of the CNS (general and specific)
-Meninges- around the brain and spinal cord
1 dura mater- the outermost membrane, dense
2 Archnoid- middle spiderlike layer (location of CSF)
3 Pia mater- innermost delicate layer (adheared to spinal cord.
Describe the location of the cerebrospinal fluid (CSF)
Subarachnoid space
name the space and location where anesthetics are given
- given in the dura mater, in the epidural space
- they are given at L2 or below to reduce risk of hitting spinal cord
Describe the parts of the gray matter of the spinal cord
- no myolin-it would contain neuron cell bodies, and unmyelinated neurons.
- located in the center of the spinal cord (central Canal)
- contains CSF
- Posterior (dorsal) horns=sensory pathway
- anterior (ventral) horns=motor pathways
Describe the parts of the white matter of the spinal cord
- myolin present
- The lateral, dorsal (posterior) and ventral (anterior) columns. (based on location)
Describe the function of the ascending and descending tracts
- with in the white matter=
- Ascending=sensory (towards brain)
- Descending tracts=Motor (away from brain) U.M.N- upper motor neurons (cns)
reflex
fast-involuntary-repeatable
-reaction to a stimulus
Spinal reflex
-If it involves the spinal cord it is a spinal reflex.
somatic reflex
-A somatic reflex terminates in skeletal muscle
autonomic reflex
-terminates in smooth muscle, cardiac muscle and glands.
Describe the pathways of a generalized reflex arc
- receptor (dendrite that interperates stimulus)
- sensory (afferent) neuron
- spinal cord (CNS)
- motor (efferent) neuron
- Effector (skeletal muscle)